f2fs: fix to check upper boundary for value of gc_boost_zoned_gc_percent

to check the upper boundary when setting gc_boost_zoned_gc_percent

Fixes: 9a481a1c ("f2fs: create gc_no_zoned_gc_percent and gc_boost_zoned_gc_percent")
Signed-off-by: yohan.joung <yohan.joung@sk.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>